xref: /csrg-svn/old/more/more.c (revision 3456)
1 static	char *sccsid = "@(#)more.c	4.3 (Berkeley) 81/04/02";
2 /*
3 ** more.c - General purpose tty output filter and file perusal program
4 **
5 **	by Eric Shienbrood, UC Berkeley
6 */
7 
8 #include <whoami.h>
9 #ifdef V6
10 #include <retrofit.h>
11 #endif
12 #include <stdio.h>
13 #include <ctype.h>
14 #include <signal.h>
15 #include <errno.h>
16 #include <sgtty.h>
17 #include <setjmp.h>
18 #include <sys/types.h>
19 #include <sys/dir.h>
20 #include <sys/stat.h>
21 #include <local/uparm.h>
22 
23 /* Help file will eventually go in libpath(more.help) on all systems */
24 
25 #ifdef INGRES
26 #define VI		"/usr/bin/vi"
27 #define HELPFILE	"/mntp/doucette/more/more.help"
28 #endif
29 
30 #ifndef INGRES
31 #ifndef HELPFILE
32 #define HELPFILE	libpath(more.help)
33 #endif
34 #define VI		binpath(vi)
35 #endif
36 
37 #define Fopen(s,m)	(Currline = 0,file_pos=0,fopen(s,m))
38 #define Ftell(f)	file_pos
39 #define Fseek(f,off)	(file_pos=off,fseek(f,off,0))
40 #define Getc(f)		(++file_pos, getc(f))
41 #define Ungetc(c,f)	(--file_pos, ungetc(c,f))
42 
43 #ifdef V6
44 #define MBIT	RAW
45 #define CBREAK	~RAW
46 #else
47 #define MBIT	CBREAK
48 #define stty(fd,argp)	ioctl(fd,TIOCSETN,argp)
49 #endif
50 
51 #define TBUFSIZ	1024
52 #define LINSIZ	256
53 #define ctrl(letter)	('letter' & 077)
54 #define RUBOUT	'\177'
55 #define ESC	'\033'
56 #define QUIT	'\034'
57 
58 struct sgttyb 	otty;
59 long		file_pos, file_size;
60 int		fnum, no_intty, no_tty, slow_tty;
61 int		dum_opt, dlines, onquit(), end_it();
62 #ifdef SIGTSTP
63 int		onsusp();
64 #endif
65 int		nscroll = 11;	/* Number of lines scrolled by 'd' */
66 int		fold_opt = 1;	/* Fold long lines */
67 int		stop_opt = 1;	/* Stop after form feeds */
68 int		promptlen;
69 int		Currline;	/* Line we are currently at */
70 int		startup = 1;
71 int		firstf = 1;
72 int		notell = 1;
73 int		bad_so;	/* True if overwriting does not turn off standout */
74 int		inwait, Pause, errors;
75 int		within;	/* true if we are within a file,
76 			false if we are between files */
77 int		hard, dumb, noscroll, hardtabs,clreol;
78 int		catch_susp;	/* We should catch the SIGTSTP signal */
79 char		**fnames;	/* The list of file names */
80 int		nfiles;		/* Number of files left to process */
81 char		*shell;		/* The name of the shell to use */
82 int		shellp;		/* A previous shell command exists */
83 char		ch;
84 jmp_buf		restore;
85 char		obuf[BUFSIZ];	/* stdout buffer */
86 char		Line[LINSIZ];	/* Line buffer */
87 int		Lpp = 24;	/* lines per page */
88 char		*Clear;		/* clear screen */
89 char		*eraseln;	/* erase line */
90 char		*Senter, *Sexit;/* enter and exit standout mode */
91 char		*Home;		/* go to home */
92 char		*cursorm;	/* cursor movement */
93 char		cursorhome[40];	/* contains cursor movement to home */
94 char		*Cleareod;	/* clear rest of screen */
95 char		*tgetstr();
96 int		Mcol = 80;	/* number of columns */
97 int		Wrap = 1;	/* set if automargins */
98 long		fseek();
99 char		*getenv();
100 struct {
101     long chrctr, line;
102 } context, screen_start;
103 extern char	PC;		/* pad character */
104 extern short	ospeed;
105 
106 
107 main(argc, argv)
108 int argc;
109 char *argv[];
110 {
111     register FILE	*f;
112     register char	*s;
113     register char	*p;
114     register char	ch;
115     register int	left;
116     int			prnames = 0;
117     int			initopt = 0;
118     int			srchopt = 0;
119     int			clearit = 0;
120     int			initline;
121     char		initbuf[80];
122     FILE		*checkf();
123 
124     nfiles = argc;
125     fnames = argv;
126     initterm ();
127     if(s = getenv("MORE")) argscan(s);
128     while (--nfiles > 0) {
129 	if ((ch = (*++fnames)[0]) == '-') {
130 	    argscan(*fnames+1);
131 	}
132 	else if (ch == '+') {
133 	    s = *fnames;
134 	    if (*++s == '/') {
135 		srchopt++;
136 		for (++s, p = initbuf; p < initbuf + 79 && *s != '\0';)
137 		    *p++ = *s++;
138 		*p = '\0';
139 	    }
140 	    else {
141 		initopt++;
142 		for (initline = 0; *s != '\0'; s++)
143 		    if (isdigit (*s))
144 			initline = initline*10 + *s -'0';
145 		--initline;
146 	    }
147 	}
148 	else break;
149     }
150     /* allow clreol only if Home and eraseln and Cleareod strings are
151      *  defined, and in that case, make sure we are in noscroll mode
152      */
153     if(clreol)
154     {
155 	if((*Home == '\0') || (*eraseln == '\0') || (*Cleareod == '\0'))
156 	   clreol = 0;
157 	else noscroll = 1;
158     }
159 
160     if (dlines == 0)
161 	dlines = Lpp - (noscroll ? 1 : 2);
162     left = dlines;
163     if (nfiles > 1)
164 	prnames++;
165     if (!no_intty && nfiles == 0) {
166 	fputs("Usage: ",stderr);
167 	fputs(argv[0],stderr);
168 	fputs(" [-dfln] [+linenum | +/pattern] name1 name2 ...\n",stderr);
169 	exit(1);
170     }
171     else
172 	f = stdin;
173     if (!no_tty) {
174 	signal(SIGQUIT, onquit);
175 	signal(SIGINT, end_it);
176 #ifdef SIGTSTP
177 	if (signal (SIGTSTP, SIG_IGN) == SIG_DFL) {
178 	    signal(SIGTSTP, onsusp);
179 	    catch_susp++;
180 	}
181 #endif
182 	stty (2, &otty);
183     }
184     if (no_intty) {
185 	if (no_tty)
186 	    copy_file (stdin);
187 	else {
188 	    if ((ch = Getc (f)) == '\f')
189 		doclear ();
190 	    else {
191 		Ungetc (ch, f);
192 		if (noscroll && (ch != EOF))
193 		{ if(clreol) home();
194 		  else doclear ();
195 		}
196 	    }
197 	    if (srchopt)
198 	    {
199 		search (initbuf, stdin, 1);
200 		if(noscroll) left--;
201 	    }
202 	    else if (initopt)
203 		skiplns (initline, stdin);
204 	    screen (stdin, left);
205 	}
206 	no_intty = 0;
207 	prnames++;
208 	firstf = 0;
209     }
210 
211     while (fnum < nfiles) {
212 	if ((f = checkf (fnames[fnum], &clearit)) != NULL) {
213 	    context.line = context.chrctr = 0;
214 	    Currline = 0;
215 	    if (firstf) setjmp (restore);
216 	    if (firstf) {
217 		firstf = 0;
218 		if (srchopt)
219 		{
220 		    search (initbuf, f, 1);
221 		    if(noscroll) left--;
222 		}
223 		else if (initopt)
224 		    skiplns (initline, f);
225 	    }
226 	    else if (fnum < nfiles && !no_tty) {
227 		setjmp (restore);
228 		left = command (fnames[fnum], f);
229 	    }
230 	    if (left != 0) {
231 		if((noscroll  || clearit) && (file_size != 0x7fffffffffffffffL))
232 		    if(clreol) home();
233 		    else doclear ();
234 		if (prnames) {
235 		    if (bad_so)
236 			erase (0);
237 		    if(clreol)cleareol();
238 		    pr("::::::::::::::");
239 		    if (promptlen > 14)
240 			erase (14);
241 		    printf ("\n");
242 		    if(clreol) cleareol();
243 		    printf("%s\n", fnames[fnum]);
244 		    if(clreol) cleareol();
245 		    printf("::::::::::::::\n", fnames[fnum]);
246 		    if (left > Lpp - 4)
247 			left = Lpp - 4;
248 		}
249 		if (no_tty)
250 		    copy_file (f);
251 		else {
252 		    within++;
253 		    screen(f, left);
254 		    within = 0;
255 		}
256 	    }
257 	    setjmp (restore);
258 	    fflush(stdout);
259 	    fclose(f);
260 	    screen_start.line = screen_start.chrctr = 0L;
261 	    context.line = context.chrctr = 0L;
262 	}
263 	fnum++;
264 	firstf = 0;
265     }
266     reset_tty ();
267     exit(0);
268 }
269 
270 argscan(s)
271 char *s;
272 {
273 	    for (dlines = 0; *s != '\0'; s++)
274 		if (isdigit(*s))
275 		    dlines = dlines*10 + *s - '0';
276 		else if (*s == 'd')
277 		    dum_opt = 1;
278 		else if (*s == 'l')
279 		    stop_opt = 0;
280 		else if (*s == 'f')
281 		    fold_opt = 0;
282 		else if (*s == 'p')
283 		    noscroll++;
284 		else if (*s == 'c')
285 		    clreol++;
286 }
287 
288 
289 /*
290 
291 ** Check whether the file named by fs is an ASCII file which the user may
292 ** access.  If it is, return the opened file. Otherwise return NULL.
293 */
294 
295 FILE *
296 checkf (fs, clearfirst)
297 register char *fs;
298 int *clearfirst;
299 {
300     struct stat stbuf;
301     register FILE *f;
302     char c;
303 
304     if (stat (fs, &stbuf) == -1) {
305 	fflush(stdout);
306 	if(clreol)cleareol();
307 	perror(fs);
308 	return (NULL);
309     }
310     if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
311 	printf("\n*** %s: directory ***\n\n", fs);
312 	return (NULL);
313     }
314     if ((f=Fopen(fs, "r")) == NULL) {
315 	fflush(stdout);
316 	perror(fs);
317 	return (NULL);
318     }
319     c = Getc(f);
320 
321     /* Try to see whether it is an ASCII file */
322 
323     switch ((c | *f->_ptr << 8) & 0177777) {
324     case 0405:
325     case 0407:
326     case 0410:
327     case 0411:
328     case 0413:
329     case 0177545:
330 	printf("\n******** %s: Not a text file ********\n\n", fs);
331 	fclose (f);
332 	return (NULL);
333     default:
334 	break;
335     }
336     if (c == '\f')
337 	*clearfirst = 1;
338     else {
339 	*clearfirst = 0;
340 	Ungetc (c, f);
341     }
342     if ((file_size = stbuf.st_size) == 0)
343 	file_size = 0x7fffffffffffffffL;
344     return (f);
345 }
346 
347 /*
348 ** A real function, for the tputs routine in termlib
349 */
350 
351 putch (ch)
352 char ch;
353 {
354     putchar (ch);
355 }
356 
357 /*
358 ** Print out the contents of the file f, one screenful at a time.
359 */
360 
361 #define STOP -10
362 
363 screen (f, num_lines)
364 register FILE *f;
365 register int num_lines;
366 {
367     register int c;
368     register int nchars;
369     int length;
370 
371     for (;;) {
372 	while (num_lines > 0 && !Pause) {
373 	    if ((nchars = getline (f, &length)) == EOF)
374 	    {
375 		if(clreol) cleareod();
376 		return;
377 	    }
378 	    if (bad_so || (Senter && *Senter == ' ') && promptlen > 0)
379 		erase (0);
380 	    if (clreol) cleareol();
381 	    prbuf (Line, length);
382 	    if (nchars < promptlen)
383 		erase (nchars);	/* erase () sets promptlen to 0 */
384 	    else promptlen = 0;
385 	    if (nchars < Mcol || !fold_opt)
386 		putchar('\n');
387 	    if (nchars == STOP)
388 		break;
389 	    num_lines--;
390 	}
391 	fflush(stdout);
392 	if ((c = Getc(f)) == EOF)
393 	{
394 	    if(clreol) cleareod();
395 	    return;
396 	}
397 
398 	if(Pause && clreol) cleareod();
399 
400 	Ungetc (c, f);
401 	setjmp (restore);
402 	Pause = 0; startup = 0;
403 	if ((num_lines = command (NULL, f)) == 0)
404 	    return;
405 	if (hard && promptlen > 0)
406 		erase (0);
407 	if (noscroll && num_lines == dlines)
408 	{
409 	    if(clreol) home();
410 	    else doclear ();
411 	}
412 	screen_start.line = Currline;
413 	screen_start.chrctr = Ftell (f);
414     }
415 }
416 
417 /*
418 ** Come here if a quit signal is received
419 */
420 
421 onquit()
422 {
423     signal(SIGQUIT, SIG_IGN);
424     if (!inwait) {
425 	putchar ('\n');
426 	if (!startup) {
427 	    signal(SIGQUIT, onquit);
428 	    longjmp (restore, 1);
429 	}
430 	else
431 	    Pause++;
432     }
433     else if (!dum_opt && notell) {
434 	write (2, "[Use q or Q to quit]", 20);
435 	promptlen += 20;
436 	notell = 0;
437     }
438     signal(SIGQUIT, onquit);
439 }
440 
441 /*
442 ** Clean up terminal state and exit. Also come here if interrupt signal received
443 */
444 
445 end_it ()
446 {
447 
448     reset_tty ();
449     if(clreol) { putchar('\r'); cleareod(); fflush(stdout); }
450     else if (!clreol && (promptlen > 0)) {
451 	kill_line ();
452 	fflush (stdout);
453     }
454     else
455 	write (2, "\n", 1);
456     _exit(0);
457 }
458 
459 copy_file(f)
460 register FILE *f;
461 {
462     register int c;
463 
464     while ((c = getc(f)) != EOF)
465 	putchar(c);
466 }
467 
468 /* Simplified printf function */
469 
470 printf (fmt, args)
471 register char *fmt;
472 int args;
473 {
474 	register int *argp;
475 	register char ch;
476 	register int ccount;
477 
478 	ccount = 0;
479 	argp = &args;
480 	while (*fmt) {
481 		while ((ch = *fmt++) != '%') {
482 			if (ch == '\0')
483 				return (ccount);
484 			ccount++;
485 			putchar (ch);
486 		}
487 		switch (*fmt++) {
488 		case 'd':
489 			ccount += printd (*argp);
490 			break;
491 		case 's':
492 			ccount += pr ((char *)*argp);
493 			break;
494 		case '%':
495 			ccount++;
496 			argp--;
497 			putchar ('%');
498 			break;
499 		case '0':
500 			return (ccount);
501 		default:
502 			break;
503 		}
504 		++argp;
505 	}
506 	return (ccount);
507 
508 }
509 
510 /*
511 ** Print an integer as a string of decimal digits,
512 ** returning the length of the print representation.
513 */
514 
515 printd (n)
516 int n;
517 {
518     int a, nchars;
519 
520     if (a = n/10)
521 	nchars = 1 + printd(a);
522     else
523 	nchars = 1;
524     putchar (n % 10 + '0');
525     return (nchars);
526 }
527 
528 /* Put the print representation of an integer into a string */
529 static char *sptr;
530 
531 scanstr (n, str)
532 int n;
533 char *str;
534 {
535     sptr = str;
536     sprintf (n);
537     *sptr = '\0';
538 }
539 
540 sprintf (n)
541 {
542     int a;
543 
544     if (a = n/10)
545 	sprintf (a);
546     *sptr++ = n % 10 + '0';
547 }
548 
549 static char bell = ctrl(G);
550 
551 strlen (s)
552 char *s;
553 {
554     register char *p;
555 
556     p = s;
557     while (*p++)
558 	;
559     return (p - s - 1);
560 }
561 
562 /* See whether the last component of the path name "path" is equal to the
563 ** string "string"
564 */
565 
566 tailequ (path, string)
567 char *path;
568 register char *string;
569 {
570 	register char *tail;
571 
572 	tail = path + strlen(path);
573 	while (tail >= path)
574 		if (*(--tail) == '/')
575 			break;
576 	++tail;
577 	while (*tail++ == *string++)
578 		if (*tail == '\0')
579 			return(1);
580 	return(0);
581 }
582 
583 prompt (filename)
584 char *filename;
585 {
586     if(clreol)cleareol();
587     else if (promptlen > 0)
588 	kill_line ();
589     if (!hard) {
590 	promptlen = 8;
591 	if (Senter && Sexit)
592 	    tputs (Senter, 1, putch);
593 	if(clreol)cleareol();
594 	pr("--More--");
595 	if (filename != NULL) {
596 	    promptlen += printf ("(Next file: %s)", filename);
597 	}
598 	else if (!no_intty) {
599 	    promptlen += printf ("(%d%%)", (int)((file_pos * 100) / file_size));
600 	}
601 	if (dum_opt) {
602 	    promptlen += pr("[Hit space to continue, Rubout to abort]");
603 	}
604 	if (Senter && Sexit)
605 	    tputs (Sexit, 1, putch);
606 	fflush(stdout);
607     }
608     else
609 	write (2, &bell, 1);
610     inwait++;
611 }
612 
613 /*
614 ** Get a logical line
615 */
616 
617 getline(f, length)
618 register FILE *f;
619 int *length;
620 {
621     register int	c;
622     register char	*p;
623     register int	column;
624     static int		colflg;
625 
626     p = Line;
627     column = 0;
628     c = Getc (f);
629     if (colflg && c == '\n') {
630 	Currline++;
631 	c = Getc (f);
632     }
633     while (p < &Line[LINSIZ - 1]) {
634 	if (c == EOF) {
635 	    if (p > Line) {
636 		*p = '\0';
637 		*length = p - Line;
638 		return (column);
639 	    }
640 	    *length = p - Line;
641 	    return (EOF);
642 	}
643 	if (c == '\n') {
644 	    Currline++;
645 	    break;
646 	}
647 	*p++ = c;
648 	if (c == '\t')
649 	    if (hardtabs && column < promptlen && !hard) {
650 		if (eraseln && !dumb) {
651 		    column = 1 + (column | 7);
652 		    tputs (eraseln, 1, putch);
653 		    promptlen = 0;
654 		}
655 		else {
656 		    for (--p; column & 7 && p < &Line[LINSIZ - 1]; column++) {
657 			*p++ = ' ';
658 		    }
659 		    if (column >= promptlen) promptlen = 0;
660 		}
661 	    }
662 	    else
663 		column = 1 + (column | 7);
664 	else if (c == '\b')
665 	    column--;
666 	else if (c == '\r')
667 	    column = 0;
668 	else if (c == '\f' && stop_opt) {
669 		p[-1] = '^';
670 		*p++ = 'L';
671 		column += 2;
672 		Pause++;
673 	}
674 	else if (c == EOF) {
675 	    *length = p - Line;
676 	    return (column);
677 	}
678 	else if (c >= ' ' && c != RUBOUT)
679 	    column++;
680 	if (column >= Mcol && fold_opt) break;
681 	c = Getc (f);
682     }
683     if (column >= Mcol && Mcol > 0) {
684 	if (!Wrap) {
685 	    *p++ = '\n';
686 	}
687     }
688     colflg = column == Mcol && fold_opt;
689     *length = p - Line;
690     *p = 0;
691     return (column);
692 }
693 
694 /*
695 ** Erase the rest of the prompt, assuming we are starting at column col.
696 */
697 
698 erase (col)
699 register int col;
700 {
701 
702     if (promptlen == 0)
703 	return;
704     if (hard) {
705 	putchar ('\n');
706     }
707     else {
708 	if (col == 0)
709 	    putchar ('\r');
710 	if (!dumb && eraseln)
711 	    tputs (eraseln, 1, putch);
712 	else
713 	    for (col = promptlen - col; col > 0; col--)
714 		putchar (' ');
715     }
716     promptlen = 0;
717 }
718 
719 /*
720 ** Erase the current line entirely
721 */
722 
723 kill_line ()
724 {
725     erase (0);
726     if (!eraseln || dumb) putchar ('\r');
727 }
728 
729 /*
730  * force clear to end of line
731  */
732 cleareol()
733 {
734     tputs(eraseln,1,putch);
735 }
736 
737 cleareod()
738 {
739     tputs(Cleareod,1,putch);
740 }
741 
742 /*
743 **  Print string and return number of characters
744 */
745 
746 pr(s1)
747 char	*s1;
748 {
749     register char	*s;
750     register char	c;
751 
752     for (s = s1; c = *s++; )
753 	putchar(c);
754     return (s - s1 - 1);
755 }
756 
757 
758 /* Print a buffer of n characters */
759 
760 prbuf (s, n)
761 register char *s;
762 register int n;
763 {
764     while (n-- > 0)
765 	putchar (*s++);
766 }
767 
768 /*
769 **  Clear the screen
770 */
771 
772 doclear()
773 {
774     if (Clear && !hard) {
775 	tputs(Clear, 1, putch);
776 
777 	/* Put out carriage return so that system doesn't
778 	** get confused by escape sequences when expanding tabs
779 	*/
780 	putchar ('\r');
781 	promptlen = 0;
782     }
783 }
784 
785 /*
786  * Go to home position
787  */
788 home()
789 {
790     tputs(Home,1,putch);
791 }
792 
793 static int lastcmd, lastarg, lastp;
794 static int lastcolon;
795 char shell_line[132];
796 
797 /*
798 ** Read a command and do it. A command consists of an optional integer
799 ** argument followed by the command character.  Return the number of lines
800 ** to display in the next screenful.  If there is nothing more to display
801 ** in the current file, zero is returned.
802 */
803 
804 command (filename, f)
805 char *filename;
806 register FILE *f;
807 {
808     register int nlines;
809     register int retval;
810     register char c;
811     char colonch;
812     FILE *helpf;
813     int done;
814     char comchar, cmdbuf[80], *p;
815 
816 #define ret(val) retval=val;done++;break
817 
818     done = 0;
819     if (!errors)
820 	prompt (filename);
821     else
822 	errors = 0;
823     if (MBIT == RAW && slow_tty) {
824 	otty.sg_flags |= MBIT;
825 	stty(2, &otty);
826     }
827     for (;;) {
828 	nlines = number (&comchar);
829 	lastp = colonch = 0;
830 	if (comchar == '.') {	/* Repeat last command */
831 		lastp++;
832 		comchar = lastcmd;
833 		nlines = lastarg;
834 		if (lastcmd == ':')
835 			colonch = lastcolon;
836 	}
837 	lastcmd = comchar;
838 	lastarg = nlines;
839 	if (comchar == otty.sg_erase) {
840 	    kill_line ();
841 	    prompt (filename);
842 	    continue;
843 	}
844 	switch (comchar) {
845 	case ':':
846 	    retval = colon (filename, colonch, nlines);
847 	    if (retval >= 0)
848 		done++;
849 	    break;
850 	case ' ':
851 	case 'z':
852 	    if (nlines == 0) nlines = dlines;
853 	    else if (comchar == 'z') dlines = nlines;
854 	    ret (nlines);
855 	case 'd':
856 	case ctrl(D):
857 	    if (nlines != 0) nscroll = nlines;
858 	    ret (nscroll);
859 	case RUBOUT:
860 	case 'q':
861 	case 'Q':
862 	    end_it ();
863 	case 's':
864 	case 'f':
865 	    if (nlines == 0) nlines++;
866 	    if (comchar == 'f')
867 		nlines *= dlines;
868 	    putchar ('\r');
869 	    erase (0);
870 	    printf("\n");
871 	    if(clreol)cleareol();
872 	    printf("...skipping %d line", nlines);
873 	    if (nlines > 1)
874 	    {
875 		pr("s\n");
876 	        if(clreol)cleareol();
877 		pr("\n");
878 	    }
879 	    else
880 	    {
881 		pr("\n");
882 	        if(clreol)cleareol();
883 		pr("\n");
884 	    }
885 	    while (nlines > 0) {
886 		while ((c = Getc (f)) != '\n')
887 		    if (c == EOF) {
888 			retval = 0;
889 			done++;
890 			goto endsw;
891 		    }
892 		    Currline++;
893 		    nlines--;
894 	    }
895 	    ret (dlines);
896 	case '\n':
897 	    if (nlines != 0)
898 		dlines = nlines;
899 	    else
900 		nlines = 1;
901 	    ret (nlines);
902 	case '\f':
903 	    if (!no_intty) {
904 		doclear ();
905 		Fseek (f, screen_start.chrctr);
906 		Currline = screen_start.line;
907 		ret (dlines);
908 	    }
909 	    else {
910 		write (2, &bell, 1);
911 		break;
912 	    }
913 	case '\'':
914 	    if (!no_intty) {
915 		kill_line ();
916 		pr ("\n***Back***\n\n");
917 		Fseek (f, context.chrctr);
918 		Currline = context.line;
919 		ret (dlines);
920 	    }
921 	    else {
922 		write (2, &bell, 1);
923 		break;
924 	    }
925 	case '=':
926 	    kill_line ();
927 	    promptlen = printd (Currline);
928 	    fflush (stdout);
929 	    break;
930 	case 'n':
931 	    lastp++;
932 	case '/':
933 	    if (nlines == 0) nlines++;
934 	    kill_line ();
935 	    pr ("/");
936 	    promptlen = 1;
937 	    fflush (stdout);
938 	    if (lastp) {
939 		write (2,"\r", 1);
940 		search (NULL, f, nlines);	/* Use previous r.e. */
941 	    }
942 	    else {
943 		ttyin (cmdbuf, 78, '/');
944 		write (2, "\r", 1);
945 		search (cmdbuf, f, nlines);
946 	    }
947 	    ret (dlines-1);
948 	case '!':
949 	    do_shell (filename);
950 	    break;
951 	case 'h':
952 	    if ((helpf = fopen (HELPFILE, "r")) == NULL)
953 		error ("Can't open help file");
954 	    if (noscroll) doclear ();
955 	    copy_file (helpf);
956 	    close (helpf);
957 	    prompt (filename);
958 	    break;
959 	case 'v':	/* This case should go right before default */
960 	    if (!no_intty) {
961 		kill_line ();
962 		cmdbuf[0] = '+';
963 		scanstr (Currline, &cmdbuf[1]);
964 		pr ("vi "); pr (cmdbuf); putchar (' '); pr (fnames[fnum]);
965 		execute (filename, VI, "vi", cmdbuf, fnames[fnum], 0);
966 		break;
967 	    }
968 	default:
969 	    write (2, &bell, 1);
970 	    break;
971 	}
972 	if (done) break;
973     }
974     putchar ('\r');
975 endsw:
976     inwait = 0;
977     notell++;
978     if (MBIT == RAW && slow_tty) {
979 	otty.sg_flags &= ~MBIT;
980 	stty(2, &otty);
981     }
982     return (retval);
983 }
984 
985 char ch;
986 
987 /*
988  * Execute a colon-prefixed command.
989  * Returns <0 if not a command that should cause
990  * more of the file to be printed.
991  */
992 
993 colon (filename, cmd, nlines)
994 char *filename;
995 int cmd;
996 int nlines;
997 {
998 	if (cmd == 0)
999 		ch = readch ();
1000 	else
1001 		ch = cmd;
1002 	lastcolon = ch;
1003 	switch (ch) {
1004 	case 'f':
1005 		kill_line ();
1006 		if (!no_intty)
1007 			promptlen = printf ("\"%s\" line %d", fnames[fnum], Currline);
1008 		else
1009 			promptlen = printf ("[Not a file] line %d", Currline);
1010 		fflush (stdout);
1011 		return (-1);
1012 	case 'n':
1013 		if (nlines == 0) {
1014 			if (fnum >= nfiles - 1)
1015 				end_it ();
1016 			nlines++;
1017 		}
1018 		putchar ('\r');
1019 		erase (0);
1020 		skipf (nlines);
1021 		return (0);
1022 	case 'p':
1023 		if (no_intty) {
1024 			write (2, &bell, 1);
1025 			return (-1);
1026 		}
1027 		putchar ('\r');
1028 		erase (0);
1029 		if (nlines == 0)
1030 			nlines++;
1031 		skipf (-nlines);
1032 		return (0);
1033 	case '!':
1034 		do_shell (filename);
1035 		return (-1);
1036 	case 'q':
1037 	case 'Q':
1038 		end_it ();
1039 	default:
1040 		write (2, &bell, 1);
1041 		return (-1);
1042 	}
1043 }
1044 
1045 /*
1046 ** Read a decimal number from the terminal. Set cmd to the non-digit which
1047 ** terminates the number.
1048 */
1049 
1050 number(cmd)
1051 char *cmd;
1052 {
1053 	register int i;
1054 
1055 	i = 0; ch = otty.sg_kill;
1056 	for (;;) {
1057 		ch = readch ();
1058 		if (ch >= '0' && ch <= '9')
1059 			i = i*10 + ch - '0';
1060 		else if (ch == otty.sg_kill)
1061 			i = 0;
1062 		else {
1063 			*cmd = ch;
1064 			break;
1065 		}
1066 	}
1067 	return (i);
1068 }
1069 
1070 do_shell (filename)
1071 char *filename;
1072 {
1073 	char cmdbuf[80];
1074 
1075 	kill_line ();
1076 	pr ("!");
1077 	fflush (stdout);
1078 	promptlen = 1;
1079 	if (lastp)
1080 		pr (shell_line);
1081 	else {
1082 		ttyin (cmdbuf, 78, '!');
1083 		if (expand (shell_line, cmdbuf)) {
1084 			kill_line ();
1085 			promptlen = printf ("!%s", shell_line);
1086 		}
1087 	}
1088 	fflush (stdout);
1089 	write (2, "\n", 1);
1090 	promptlen = 0;
1091 	shellp = 1;
1092 	execute (filename, shell, shell, "-c", shell_line, 0);
1093 }
1094 
1095 /*
1096 ** Search for nth ocurrence of regular expression contained in buf in the file
1097 */
1098 
1099 search (buf, file, n)
1100 char buf[];
1101 FILE *file;
1102 register int n;
1103 {
1104     long startline = Ftell (file);
1105     register long line1 = startline;
1106     register long line2 = startline;
1107     register long line3 = startline;
1108     register int lncount;
1109     int saveln, rv, re_exec();
1110     char *s, *re_comp();
1111 
1112     context.line = saveln = Currline;
1113     context.chrctr = startline;
1114     lncount = 0;
1115     if ((s = re_comp (buf)) != 0)
1116 	error (s);
1117     while (!feof (file)) {
1118 	line3 = line2;
1119 	line2 = line1;
1120 	line1 = Ftell (file);
1121 	rdline (file);
1122 	lncount++;
1123 	if ((rv = re_exec (Line)) == 1)
1124 		if (--n == 0) {
1125 		    if (lncount > 3 || (lncount > 1 && no_intty))
1126 		    {
1127 			pr ("\n");
1128 			if(clreol) cleareol();
1129 			pr("...skipping\n");
1130 		    }
1131 		    if (!no_intty) {
1132 			Currline -= (lncount >= 3 ? 3 : lncount);
1133 			Fseek (file, line3);
1134 			if(noscroll)
1135 			  if(clreol)
1136 			  {
1137 			     home();
1138 			     cleareol();
1139 			  }
1140 			  else doclear();
1141 		    }
1142 		    else {
1143 			kill_line ();
1144 			if(noscroll)
1145 			  if(clreol)
1146 			  {
1147 			     home();
1148 			     cleareol();
1149 			  }
1150 			  else doclear();
1151 			pr (Line);
1152 			putchar ('\n');
1153 		    }
1154 		    break;
1155 		}
1156 	else if (rv == -1)
1157 	    error ("Regular expression botch");
1158     }
1159     if (feof (file)) {
1160 	if (!no_intty) {
1161 #ifdef V6
1162 	    file->_flag &= ~_IOEOF; /* why doesn't fseek do this ??!!??! */
1163 #endif
1164 	    Currline = saveln;
1165 	    Fseek (file, startline);
1166 	}
1167 	else {
1168 	    pr ("\nPattern not found\n");
1169 	    end_it ();
1170 	}
1171 	error ("Pattern not found");
1172     }
1173 }
1174 
1175 execute (filename, cmd, args)
1176 char *filename;
1177 char *cmd, *args;
1178 {
1179 	int id;
1180 
1181 	fflush (stdout);
1182 	reset_tty ();
1183 	while ((id = fork ()) < 0)
1184 	    sleep (5);
1185 	if (id == 0) {
1186 	    execv (cmd, &args);
1187 	    write (2, "exec failed\n", 12);
1188 	    exit (1);
1189 	}
1190 	signal (SIGINT, SIG_IGN);
1191 	signal (SIGQUIT, SIG_IGN);
1192 #ifdef SIGTSTP
1193 	if (catch_susp)
1194 	    signal(SIGTSTP, SIG_DFL);
1195 #endif
1196 	wait (0);
1197 	signal (SIGINT, end_it);
1198 	signal (SIGQUIT, onquit);
1199 #ifdef SIGTSTP
1200 	if (catch_susp)
1201 	    signal(SIGTSTP, onsusp);
1202 #endif
1203 	set_tty ();
1204 	pr ("------------------------\n");
1205 	prompt (filename);
1206 }
1207 /*
1208 ** Skip n lines in the file f
1209 */
1210 
1211 skiplns (n, f)
1212 register int n;
1213 register FILE *f;
1214 {
1215     register char c;
1216 
1217     while (n > 0) {
1218 	while ((c = Getc (f)) != '\n')
1219 	    if (c == EOF)
1220 		return;
1221 	    n--;
1222 	    Currline++;
1223     }
1224 }
1225 
1226 /*
1227 ** Skip nskip files in the file list (from the command line). Nskip may be
1228 ** negative.
1229 */
1230 
1231 skipf (nskip)
1232 register int nskip;
1233 {
1234     if (nskip == 0) return;
1235     if (nskip > 0) {
1236 	if (fnum + nskip > nfiles - 1)
1237 	    nskip = nfiles - fnum - 1;
1238     }
1239     else if (within)
1240 	++fnum;
1241     fnum += nskip;
1242     if (fnum < 0)
1243 	fnum = 0;
1244     pr ("\n");
1245     if (clreol) cleareol();
1246     pr ("...Skipping ");
1247     pr (nskip > 0 ? "to file " : "back to file ");
1248     pr (fnames[fnum]);
1249     pr ("\n");
1250     if (clreol) cleareol();
1251     pr ("\n");
1252     --fnum;
1253 }
1254 
1255 /*----------------------------- Terminal I/O -------------------------------*/
1256 
1257 initterm ()
1258 {
1259     char	buf[TBUFSIZ];
1260     char	clearbuf[100];
1261     char	*clearptr, *padstr;
1262     int		ldisc;
1263 
1264     setbuf(stdout, obuf);
1265     if (!(no_tty = gtty(1, &otty))) {
1266 	if (tgetent(buf, getenv("TERM")) <= 0) {
1267 	    dumb++;
1268 	}
1269 	else {
1270 	    if (((Lpp = tgetnum("li")) < 0) || tgetflag("hc")) {
1271 		hard++;	/* Hard copy terminal */
1272 		Lpp = 24;
1273 	    }
1274 	    if (tailequ (fnames[0], "page") || !hard && tgetflag("ns"))
1275 		noscroll++;
1276 	    if ((Mcol = tgetnum("co")) < 0)
1277 		Mcol = 80;
1278 	    Wrap = tgetflag("am");
1279 	    bad_so = tgetflag ("xs");
1280 	    clearptr = clearbuf;
1281 	    eraseln = tgetstr("ce",&clearptr);
1282 	    Clear = tgetstr("cl", &clearptr);
1283 	    Senter = tgetstr("so", &clearptr);
1284 	    Sexit = tgetstr("se", &clearptr);
1285 	    if (padstr = tgetstr("pc", &clearptr))
1286 		PC = *padstr;
1287 	    Home = tgetstr("ho",&clearptr);
1288 	    if(*Home == '\0')
1289 	    {
1290 	       if(*(cursorm = tgetstr("cm",&clearptr)))
1291 	       {
1292 		    strcpy(cursorhome,tgoto(cursorm,0,0));
1293 		    Home = cursorhome;
1294 	       }
1295 	    }
1296 	    Cleareod = tgetstr("cd",&clearptr);
1297 	}
1298 	if ((shell = getenv("SHELL")) == NULL)
1299 	    shell = "/bin/sh";
1300     }
1301     no_intty = gtty(0, &otty);
1302     gtty(2, &otty);
1303     ospeed = otty.sg_ospeed;
1304     slow_tty = ospeed < B1200;
1305     hardtabs =  !(otty.sg_flags & XTABS);
1306     if (!no_tty) {
1307 	otty.sg_flags &= ~ECHO;
1308 	if (MBIT == CBREAK || !slow_tty)
1309 	    otty.sg_flags |= MBIT;
1310     }
1311 }
1312 
1313 readch ()
1314 {
1315 	char ch;
1316 	extern int errno;
1317 
1318 	if (read (2, &ch, 1) <= 0)
1319 		if (errno != EINTR)
1320 			exit(0);
1321 		else
1322 			ch = otty.sg_kill;
1323 	return (ch);
1324 }
1325 
1326 static char BS = '\b';
1327 static char CARAT = '^';
1328 
1329 ttyin (buf, nmax, pchar)
1330 char buf[];
1331 register int nmax;
1332 char pchar;
1333 {
1334     register char *sptr;
1335     register char ch;
1336     register int slash = 0;
1337     int	maxlen;
1338     char cbuf;
1339 
1340     sptr = buf;
1341     maxlen = 0;
1342     while (sptr - buf < nmax) {
1343 	if (promptlen > maxlen) maxlen = promptlen;
1344 	ch = readch ();
1345 	if (ch == '\\') {
1346 	    slash++;
1347 	}
1348 	else if ((ch == otty.sg_erase) && !slash) {
1349 	    if (sptr > buf) {
1350 		--promptlen;
1351 		write (2, &BS, 1);
1352 		--sptr;
1353 		if ((*sptr < ' ' && *sptr != '\n') || *sptr == RUBOUT) {
1354 		    --promptlen;
1355 		    write (2, &BS, 1);
1356 		}
1357 		continue;
1358 	    }
1359 	    else {
1360 		if (!eraseln) promptlen = maxlen;
1361 		longjmp (restore, 1);
1362 	    }
1363 	}
1364 	else if ((ch == otty.sg_kill) && !slash) {
1365 	    if (hard) {
1366 		show (ch);
1367 		putchar ('\n');
1368 		putchar (pchar);
1369 	    }
1370 	    else {
1371 		putchar ('\r');
1372 		putchar (pchar);
1373 		if (eraseln)
1374 		    erase (1);
1375 		promptlen = 1;
1376 	    }
1377 	    sptr = buf;
1378 	    fflush (stdout);
1379 	    continue;
1380 	}
1381 	if (slash && (ch == otty.sg_kill || ch == otty.sg_erase)) {
1382 	    write (2, &BS, 1);
1383 	    --sptr;
1384 	}
1385 	if (ch != '\\')
1386 	    slash = 0;
1387 	*sptr++ = ch;
1388 	if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1389 	    ch += ch == RUBOUT ? -0100 : 0100;
1390 	    write (2, &CARAT, 1);
1391 	    promptlen++;
1392 	}
1393 	cbuf = ch;
1394 	if (ch != '\n' && ch != ESC) {
1395 	    write (2, &cbuf, 1);
1396 	    promptlen++;
1397 	}
1398 	else
1399 	    break;
1400     }
1401     *--sptr = '\0';
1402     if (!eraseln) promptlen = maxlen;
1403     if (sptr - buf >= nmax - 1)
1404 	error ("Line too long");
1405 }
1406 
1407 expand (outbuf, inbuf)
1408 char *outbuf;
1409 char *inbuf;
1410 {
1411     register char *instr;
1412     register char *outstr;
1413     register char ch;
1414     char temp[200];
1415     int changed = 0;
1416 
1417     instr = inbuf;
1418     outstr = temp;
1419     while ((ch = *instr++) != '\0')
1420 	switch (ch) {
1421 	case '%':
1422 	    if (!no_intty) {
1423 		strcpy (outstr, fnames[fnum]);
1424 		outstr += strlen (fnames[fnum]);
1425 		changed++;
1426 	    }
1427 	    else
1428 		*outstr++ = ch;
1429 	    break;
1430 	case '!':
1431 	    if (!shellp)
1432 		error ("No previous command to substitute for");
1433 	    strcpy (outstr, shell_line);
1434 	    outstr += strlen (shell_line);
1435 	    changed++;
1436 	    break;
1437 	case '\\':
1438 	    if (*instr == '%' || *instr == '!') {
1439 		*outstr++ = *instr++;
1440 		break;
1441 	    }
1442 	default:
1443 	    *outstr++ = ch;
1444 	}
1445     *outstr++ = '\0';
1446     strcpy (outbuf, temp);
1447     return (changed);
1448 }
1449 
1450 show (ch)
1451 register char ch;
1452 {
1453     char cbuf;
1454 
1455     if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1456 	ch += ch == RUBOUT ? -0100 : 0100;
1457 	write (2, &CARAT, 1);
1458 	promptlen++;
1459     }
1460     cbuf = ch;
1461     write (2, &cbuf, 1);
1462     promptlen++;
1463 }
1464 
1465 error (mess)
1466 char *mess;
1467 {
1468     if(clreol)cleareol();
1469     else kill_line ();
1470     promptlen += strlen (mess);
1471     if (Senter && Sexit) {
1472 	tputs (Senter, 1, putch);
1473 	pr(mess);
1474 	tputs (Sexit, 1, putch);
1475     }
1476     else
1477 	pr (mess);
1478     fflush(stdout);
1479     errors++;
1480     longjmp (restore, 1);
1481 }
1482 
1483 
1484 set_tty ()
1485 {
1486 	otty.sg_flags |= MBIT;
1487 	otty.sg_flags &= ~ECHO;
1488 	stty(2, &otty);
1489 }
1490 
1491 reset_tty ()
1492 {
1493     otty.sg_flags |= ECHO;
1494     otty.sg_flags &= ~MBIT;
1495     stty(2, &otty);
1496 }
1497 
1498 rdline (f)
1499 register FILE *f;
1500 {
1501     register char c;
1502     register char *p;
1503 
1504     p = Line;
1505     while ((c = Getc (f)) != '\n' && c != EOF && p - Line < LINSIZ - 1)
1506 	*p++ = c;
1507     if (c == '\n')
1508 	Currline++;
1509     *p = '\0';
1510 }
1511 
1512 /* Come here when we get a suspend signal from the terminal */
1513 
1514 #ifdef SIGTSTP
1515 onsusp ()
1516 {
1517     reset_tty ();
1518     fflush (stdout);
1519     /* Send the TSTP signal to suspend our process group */
1520     kill (0, SIGTSTP);
1521     /* Pause for station break */
1522 
1523     /* We're back */
1524     signal (SIGTSTP, onsusp);
1525     set_tty ();
1526     if (inwait)
1527 	    longjmp (restore);
1528 }
1529 #endif
1530